libgomp: OMP_PLACES
1
1 3.10 'OMP_PLACES' - Specifies on which CPUs the theads should be placed
1 =======================================================================
1
1 _Description_:
1 The thread placement can be either specified using an abstract name
1 or by an explicit list of the places. The abstract names
1 'threads', 'cores' and 'sockets' can be optionally followed by a
1 positive number in parentheses, which denotes the how many places
1 shall be created. With 'threads' each place corresponds to a
1 single hardware thread; 'cores' to a single core with the
1 corresponding number of hardware threads; and with 'sockets' the
1 place corresponds to a single socket. The resulting placement can
1 be shown by setting the 'OMP_DISPLAY_ENV' environment variable.
1
1 Alternatively, the placement can be specified explicitly as
1 comma-separated list of places. A place is specified by set of
1 nonnegative numbers in curly braces, denoting the denoting the
1 hardware threads. The hardware threads belonging to a place can
1 either be specified as comma-separated list of nonnegative thread
1 numbers or using an interval. Multiple places can also be either
1 specified by a comma-separated list of places or by an interval.
1 To specify an interval, a colon followed by the count is placed
1 after after the hardware thread number or the place. Optionally,
1 the length can be followed by a colon and the stride number -
1 otherwise a unit stride is assumed. For instance, the following
1 specifies the same places list: '"{0,1,2}, {3,4,6}, {7,8,9},
1 {10,11,12}"'; '"{0:3}, {3:3}, {7:3}, {10:3}"'; and '"{0:2}:4:3"'.
1
1 If 'OMP_PLACES' and 'GOMP_CPU_AFFINITY' are unset and
1 'OMP_PROC_BIND' is either unset or 'false', threads may be moved
1 between CPUs following no placement policy.
1
1 _See also_:
DONTPRINTYET 1 ⇒OMP_PROC_BIND, ⇒GOMP_CPU_AFFINITY, *note1DONTPRINTYET 1 ⇒OMP_PROC_BIND, ⇒GOMP_CPU_AFFINITY, ⇒
omp_get_proc_bind, ⇒OMP_DISPLAY_ENV
1
1 _Reference_:
1 OpenMP specification v4.5 (http://www.openmp.org/), Section 4.5
1